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https://dev.mysql.com/doc/refman/8.4/en/mysql-cluster-ndbinfo-counters.html
The counters table provides running totals of events such as reads and writes for specific kernel blocks and data nodes. The counters table contains the following columns: node_id The data node ID block_name Name of the associated NDB kernel block ...Counts are kept from the most recent node start or restart; a node start or restart resets all counters on that ...
https://dev.mysql.com/doc/refman/8.4/en/mysql-cluster-programs-ndbd.html
It also functions as a lock file to avoid the starting of nodes with the same identifier. It is recommended not to use a directory mounted through NFS because in some environments this can cause problems whereby the lock on the .pid file remains in ... The ndbd binary provides the single-threaded version of the process that is used to handle all the data in tables employing the NDBCLUSTER storage ...
https://dev.mysql.com/doc/refman/8.4/en/optimize-overview.html
As you work on database performance, you start by learning the high-level rules and guidelines for the software side, and measuring performance using wall-clock time. Does the application use an appropriate locking strategy? For example, by allowing ... Database performance depends on several factors at the database level, such as tables, queries, and configuration ...
https://dev.mysql.com/doc/refman/8.4/en/optimize-table.html
An exclusive table lock is only taken briefly during the prepare phase and the commit phase of the operation. Otherwise, MySQL locks the table during the time OPTIMIZE TABLE is running. OPTIMIZE TABLE reorganizes the physical storage of table data ...
https://dev.mysql.com/doc/refman/8.4/en/partitioning-limitations.html
Generally, the process executing a partitioning operation on a table takes a write lock on the table. This section discusses current restrictions and limitations on MySQL partitioning support. The following constructs are not permitted in ...
https://dev.mysql.com/doc/refman/8.4/en/performance-schema-events-waits-current-table.html
For example, if a mutex or lock is being blocked, you can check the context in which this occurs. For a synchronization object (cond, mutex, rwlock): OBJECT_SCHEMA, OBJECT_NAME, and OBJECT_TYPE are NULL. For example, it can be used with GROUP BY ...
https://dev.mysql.com/doc/refman/8.4/en/performance-schema-object-filtering.html
TABLE filtering affects table I/O events (wait/io/table/sql/handler instrument) and table lock events (wait/lock/table/sql/handler instrument). The setup_objects table controls whether the Performance Schema monitors particular table and stored ...
https://dev.mysql.com/doc/refman/8.4/en/performance-schema-quick-start.html
row *************************** THREAD_ID: 0 EVENT_ID: 5523 END_EVENT_ID: 5523 EVENT_NAME: wait/synch/mutex/mysys/THR_LOCK::mutex SOURCE: thr_lock.c:525 TIMER_START: 201660494489586 TIMER_END: 201660494576112 TIMER_WAIT: 86526 SPINS: NULL ... This ...
https://dev.mysql.com/doc/refman/8.4/en/performance-schema-restrictions.html
Tables in the performance_schema database cannot be locked with LOCK TABLES, except the setup_xxx tables. The Performance Schema avoids using mutexes to collect or produce data, so there are no guarantees of consistency and results can sometimes be ...
https://dev.mysql.com/doc/refman/8.4/en/performance-schema-setup-objects-table.html
TABLE filtering affects table I/O events (wait/io/table/sql/handler instrument) and table lock events (wait/lock/table/sql/handler instrument). The setup_objects table controls whether the Performance Schema monitors particular objects. This table ...